The virus which causes cervical cancer may also trigger some types of skin cancer, UK experts believe.

Researchers from the Imperial Cancer Research Fund (ICRF) say that Human Papillomaviruses (HPV) may be involved in the development of squamous cell carcinomas.

This type of skin cancer is often linked to organ transplant patients, whose immune systems are compromised.

It appears the virus may interact with ultraviolet light from the sun to interrupt the skin's normal defence against damage.

By killing itself the cell prevents any further damaging changes that in time can cause it to turn cancerous

Dr Alan Storey, Imperial Cancer Research Fund

The virus had been found in 80% of the squamous cell carcinomas in patients who have received an organ transplant, compared to only 30% of those with a normal immune function.

Dr Alan Storey from the ICRF's skin tumour laboratory believes that HPV acts on a protein known as "Bak" which protects skin from damaging changes.

"When a skin cell becomes too damaged to carry on working properly, for instance due to UVB radiation, Bak protein will alert the cell and tell it to undergo a programmed death.

"By killing itself the cell prevents any further damaging changes that in time can cause it to turn cancerous."

The virus seems to destroy the Bak protein so it can not perform the protective function.

Logical conclusion

Professor Normal Maitland from York University, one of the country's leading HPV researchers, says the link with certain skin cancers is a "logical conclusion".

"It seems the virus reacts with other carcinogens such as ultraviolet light - what we have to do now is find a way to diagnose the virus earlier than we do at present," he told BBC News Online.

Professor Maitland pointed out that there is also a strong link between presence of HPV and oral and laryngeal cancers.

The virus combined with environmental factors - such as smoking and sunlight - triggers cell abnormalities that become cancer.

All cases of cervical cancer are now attributed to HPV and preliminary studies suggest that between one in four men and one in five women carry the virus.

Dr Storey added: "Now we've had some success in identifying part of the complex way that this virus works, we hope that it will provide a suitable target for developing new therapies or treatments that can eliminate HPV from skin cells or limit their survival."